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Ethical, Legal and Social Implications (ELSI) of human genomics

Pharmacogenomics

Humans differ in their response to medication. Drug processing and metabolism, which relate to a medicine’s effectiveness and possible side effects, is determined in part by the genetic make-up of the individual. While other factors like inaccurate prescribing of medication, the mixing of incompatible drugs, and poor compliance on the part the patient can influence the efficacy and toxicity of medicines, a better understanding of the role of genetic variation in drug response could have important implications for the improved safety and effectiveness of treatment.

Pharmacogenetics refers to the study of DNA sequence variation as it
relates to differential drug response in individuals, i.e. the use of genomics to
determine an individuals response. Pharmacogenomics refers to the use of DNA-based
genotyping in order to target pharmaceutical agents to specific patient populations in the
design of drugs.

WHO Drug Information, Vol. 16, No.1, 2002

Clinical observations of individual differences in relation to drug toxicity and efficacy were first observed in the 1950s. Pharmacogenomics, which is in its very early stages of development, aims to uncover the genetic basis for these differences, in order to optimize design and drug therapy. Customized treatments would, in theory, mean better responsiveness, reduced side effects, and more cost effective drug development and use of drugs, because therapies would be better tailored to the populations they aim to treat.

The pharmaceutical industry is showing increasing interest in pharmacogenomics; similarly, governments, regulatory and advisory bodies in some countries are demonstrating a greater attention to this burgeoning area of research. It is important, as research in this field continues, that there is a similar growth in the understanding and ability to appropriately address the ethical, legal and social implications of pharmacogenomics. It is a field in its infancy; while evidence to data suggests reason for optimism, so far there are few applications in practice. In particular there is a lack of evidence on its impact in the context of developing countries.The complexity of human responses to medicines makes it prudent not to overestimate the probable impact of pharmacogenomics.

It is important to consider the extent to which pharmacogenomics might contribute to the further marginalization of individuals’ whose conditions—and genetic peculiarities—put them in the minority of patient populations. On the basis of genetic criteria, some conditions may be neglected as drug manufacturers focus on developing those therapies that impact on the greatest proportion of the population. Broad pharmacogenomics programmes may require obtaining extensive genetic information, which raises concerns about the appropriate protection of patients’ privacy and confidentiality. Moreover, the targeting of specific populations may result in the unfair discrimination against some groups. For instance, pharmacogenomic knowledge could be linked with specific racial or ethnic indicators, making it tempting to assume a biological linkage between race and responsiveness to particular medications, which could lead to inappropriate decisions about treatment.

Pharmacogenomics, as a new technology, will need to be carefully evaluated by countries to determine its effectiveness, including its cost-effectiveness, compared to existing public health measures. It will also be important, if pharmacogenomics is to be effectively integrated into clinical practice, to educate both the public and health professionals about its basic principles, its benefits and limitations. Because much of the information provided by pharmacogenomic tests will be probabilistic, effective communication between physicians and patients about risk will be critical to ensure informed discussion about appropriate treatment decisions.

As with most new approaches, pharmacogenomics needs to be carefully evaluated in order to determine its effectiveness relative to existing methods, and also to judge how, if applied, it would fit into the existing health care frameworks. Its integration into clinical medicine needs to take into account questions of equity and fairness, and should be accompanied by appropriate regulatory structures that ensure that patients’ privacy and confidentiality is protected.